MINNEAPOLIS -- Shortly after they finished a deal with former Carolina Panthers cornerback Captain Munnerlyn, the Minnesota Vikings were preparing to add another cornerback to their roster. According to a league source, the Vikings were finalizing a deal on Thursday night with former San Diego Chargers cornerback Derek Cox, who could add some depth to their group of defensive backs next season.

The 6-foot-1 Cox began last season as a starter for the Chargers, but lost his starting job for good after he was benched three times in four weeks last November. Cox gave up three catches and a touchdown on three targets last Nov. 24 against Kansas City, and didn't play a significant role after that. Still, he had been a serviceable player in 2012, and intercepted four passes that season for the Jaguars. He'd give the Vikings another big corner, and he'd represent a low-risk gamble by the Vikings on the ability of coach Mike Zimmer and defensive backs coach Jerry Gray to get something out of Cox.

He might also represent another closed door for a return by Chris Cook to the Vikings. The four-year player's future seemed uncertain after a conversation with Zimmer last week, and though Zimmer mentioned his ability to improve players who have a history of underachieving, like Cook does, the Vikings' order of business might tell the story better than anything else. They signed Munnerlyn and Cox on the same day Cook was scheduled to visit the San Francisco 49ers, and the Vikings now have eight cornerbacks signed for next season.